Tailoring NIPUs: Exploring the role of various diacids in non-isocyanate polyurethane synthesis

In recent deca des, numerous efforts ha ve been dedica ted to the investiga tion of eco-friendly non-isocya na te polyuretha nes (N IPU s) a s a lterna tives to conventiona l polyuretha nes (PU s). Since isocya na tes a re cla ssified by the EU a s ha za rdous a nd toxic compounds, N IPU s offer a promising route to mitiga te isocya na te-rela ted hea lth risks a s well a s other environmenta l concerns a ssocia ted with tra ditiona l PU synthesis. In the present study, we report the synthesis a s well a s the deta iled structura l a nd therma l cha ra cteriza tion of a new series of fully bioba sed non-isocya na te polyuretha nes (N IPU s) ba sed on a lipha tic dica rboxylic a cids of different cha in lengths. The N IPU s were prepa red via a two-step polya ddition rea ction involving glycerol ca rbona te a nd dia mine. Their synthesis ena bles a susta ina ble pa thwa y to ta ilor N IPU s’ physic - ochemica l properties via dia cid structure control. Studies of their structure, therma l beha vior a nd trends, morphologica l, a nd hydrolytic findings confirmed strong dia cid cha in length dependence on gla ss tra nsition tempera ture ( Tg ~13 , 0, ‒5 a nd –2 3 °C ), molecula r weight, surfa ce wetta bility, a nd enzyma tic degra da bility. Short-cha in dia cids yielded N IPU s with ra pid hydrolytic degra da tion, while their longer-cha in a na logs were hydrophobic a nd therma lly sta ble. C onta ct a ngle mea s - urements (~75–85°) a lso confirm these trends. The tuna ble properties position these ma teria ls a mong strong ca ndida tes for biomedica l a pplica tions.